I Hate Hermits!

[showjyr]

I will never again have hermit crabs in a display tank and the remaining ones I do have are banished to the fuge. I was about to drop in a few pieces of food tonight when I saw 3 hermits ripping my Emerald crab apart. He was defenseless and in mid molt. I resisted throwing them out into the snow and chucked them into my HOB fuge. Never again!

 

[SkiFletch]

opportunistic little punks huh?

 

[Donya]

What kind of hermits are they?

Hermit species have to be pretty carefully chosen for tanks and can easily be overstocked and/or run out of food, leading to those sorts of behaviors. There are also some species that just plain aren't compatible with other crustaceans.

 

[dilbert]

When I started stocking my tank I was reluctant to add those hermits and now I am reading daily horror stories about them.

It might also have to do with size of territories, food supply, and species but I guess that much from those guidelines for a clean up crew stem from larger tanks where you toss all sort of creatures into and then let go nature its way.

I have a small and relatively orderly tank where I prefer to do some jobs by myself. I got only one snail and even that spends half of the time on the live rock instead on the glass. If I would follow the often suggested stocking figures I would have 15 or even 30 snails and I don't know what they should live from.

 

[Matty P]

It can also depend on how many hermits you have for the size of your tank. It is much less risky if you have 1 hermit crab or less per 10USG.

 

[Lynden]

I have to disagree... I had to bite my tongue hard yesterday when the order form came up with red hermits (Dardanus) on the list.

Secondly, are you sure the mythrax didn't die in the molt? None of the dwarf hermits are true predators... my last giant hermit died in a molt and I knew this because the triggers were ripping his joints out of the armour. When alive the hermit could bully the five inch triggers around at will. Same deal probably applies with your mythrax.

 

[Donya]

It might also have to do with size of territories, food supply, and species but I guess that much from those guidelines for a clean up crew stem from larger tanks where you toss all sort of creatures into and then let go nature its way.

Very true. I've heard 1 hermit/gallon many times from a whole bunch of different sources, which is absolutely wrong in smaller tanks. Hermits need to be added on the basis of how much and what type of food(s) the species eats, how much hiding space there is, etc. Plus, a lot of people get hermits that are immature. They start out doing ok for food and everything, then they grow, hit maturity, etc. and the situation changes pretty drastically. I also have to target feed a number of my hermits - not all do ok on just what mucky stuff they find hidden around, and the food available for CUC isn't always constant in tanks.

None of the dwarf hermits are true predators...

Eh...I would debate this a bit. The unidentified Calcinus species I have that seems to have maxed out at 1" (still in the "dwarf" range of other similar species commonly sold, though a tad on the large side), although not a true predator in the exclusive sense, is preferentially predatory. It feeds on bristleworms and vermatid snails, only taking algae if it gets desperate and there's truely nothing else to eat. After it passed a certain size (~1/2") its diet switched from almost exclusively vegetation to almost exclusively other inverts.

 

[showjyr]

Well, these are the common blue legs that are for sale in most LFS. They are fed often on nori and pellets. I'm sure the mythrax didn't die in the molt because he was nearly out of his shell and still moving 1 claw while he was being torn apart. These were the only three hermits in the tank aside from a skeleton hermit that had nothing to do with this and seems to eat only vegetation.

I'll just never keep the a**holes in a tank again. They can roam free in the fuge and eat whatever crap makes it's way into there........wish I had a mantis tank

 

[Lynden]

Mmm... be sure to replace the hermits with whelks (Nassarius) or large amounts of bristleworms.

 

[Donya]

Well, these are the common blue legs that are for sale in most LFS. They are fed often on nori and pellets. I'm sure the mythrax didn't die in the molt because he was nearly out of his shell and still moving 1 claw while he was being torn apart. These were the only three hermits in the tank aside from a skeleton hermit that had nothing to do with this and seems to eat only vegetation.

The crab may have been alive, but it may still have been stuck. All of the true crabs I've seen have healthy sheds have done so in a matter of seconds (usually a bit of twiching followed by rocketing out the back) and then been mobile. Being part-in-part-out long enough to be slowly torn apart by something doesn't sound right.

Anyway, bluelegs are not a species I would mix with other crustaceans. They may be considered one of the more peaceful hermit species, but compared to the various species I've kept I'm not sure I would rank them as being all that peaceful. There are a number of other hermit species that are a lot less aggressive, such as electric blues and red-leg/red-tip hermits. Also, mytrhax crabs aren't great on the peacefulness scale either. I've heard of them opportunistically eating a variety of other inverts; things like that are always a risk when mixing species that aren't strict herbivores.

 

[Lynden]

Indeed this whole situation sounds a little 'fishy'...

 

[dilbert]

things like that are always a risk when mixing species that aren't strict herbivores.

That's a good point.

It's really difficult to get any peaceful cleaner crew together.

I also decided not to buy a Nassarius snail as I saw photos where a Nassarius snail has attached itself to a Turbo snail and later this Turbo snail has been found dead as the author of the photos said. Other people mentioned having lost Astrea/Turbo snail in numbers after having introduced Nassarius snails.

I noticed, too, that my two Lysmata cleaner shrimps must have eridicated most of the isopods and related animals in my tank. I don't see those small critters anymore and as I had to move some of my live rock I found that many uneaten food were rotting under these rocks when I thought those isopods et. al. would have eaten it. Today, I saw again a shrimp picking white stuff out of the live rock and eating it.

OK, those shrimps don't molest my tubeworm and another nocturnal worm stretching from its hole seems to be too cautious to be getting caught but that seems everything that is still alive.

That's because even those "peaceful" shrimps are not strictly herbivore.